Automatic fire extinguisher



p 2,1969 LGLOBERMAN ETAL 3,464,497

AUTOMATIC FIRE EXTINGUISHER Filed Jan. 23, 1968 lNVENTOR-S kmvr; 10a elm/v BY 0.55? 15? Ana/w United States Patent 3,464,497 AUTOMATIC FIRE EXTINGUISHER Irving Globerman, Westbury, and Robert S. Kaplan, Floral Park, N.Y., assignors to Ar-Kay Enterprises, Inc., Garden City, N.Y., a corporation of New York Filed Jan. 23, 1968, Ser. No. 699,828 Int. Cl. A62c 35/12, 37/06, 35/44 US. Cl. 169-2 6 Claims ABSTRACT OF THE DISCLOSURE Our invention relates to an automatic fire-extinguisher system for vehicular use, as to put out flash fires in the engine compartment of an automobile, truck, boat, etc.

Past proposals for releasing fire-extinguishing materials have relied upon fusible links, plugs or the like to detect heat, and one way or another the destruction of the fusible member is effective to release the extinguishing materials. Such systems are unduly complex, not only in regard to the number of parts which an installer must handle, but also in regard to the uncertainty of calibrationi.e., uncertainty as to the temperature of extinguisher release, as to the time to achieve such temperature response, and as to the capacity and readiness of the extinguisher to discharge. These difliculties undoubtedly account for the fact that virtually none of these systems are in use today.

It is, accordingly, an object of the invention to provide an improved extinguisher system of the character indicated.

Another object is to provide an automatic fire-extinguisher of elemental simplicity, both from the viewpoint of parts to be separately handled, and from the viewpoint of ease and fleixbility of installation.

A specific object is to meet the foregoing objects for a pressure-operated system, and at low cost.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, a preferred form of the invention:

FIG. 1 is a simplified view in side elevation showing a fire extinguisher of the invention applied to a vehicles engine compartment; and

FIG. 2 is an enlarged vertical sectional view through the body of a valve in the extinguisher of FIG. 1.

Briefly stated, the invention contemplates an automatic release mechanism for fire-extinguisher materials, operative upon detection of a given temperature condition at a localized region, as in the vicinity of the carburetor, for the case of protection against damage from a carburetor fire. Valve mechanism fits a standard extinguisher tank, and the valve is actuated by a closed liquified-gas detection system. Heat-response and the charged extent and condition of the overall installation may be readily observed and checked as frequently as desired, without dis- 3,464,497, Patented Sept. 2, 1969 ice charging the system; also, the system can be easily recharged without parts replacement.

Referring to FIG. 1 of the drawings, the invention is shown in application to the engine compartment of a vehicle. The engine 10 includes a carburetor 11 and air cleaner 12, and it is desired to automatically release extinguisher materials, such as foam, chemical or powder, upon detection of a flame temperature in the vicinity of carburetor 11. Flame temperature is detected by a closed liquefied-gas system including a bulb 14 carried by suitable clamp means 1 on or adjacent the carburetor. Bulb 14 is connected by flexible conduit 16 to the cap 17 of a pressure-responsive actuator such as a diaphragm 18 (FIG. 2), for generating valve-actuating downward displacements as gas pressure increase with heat applied at 14; the detecting system of bulb 14 may, for example, be filled with Freon. The valve has a body 19 secured to the mouth of a tank 20 for extinguisher materials. The entire assembly of tank 20, valve body 19, and cap 17 is carried by a snap-finger bracket 21 mounted on the fire wall 22 of the vehicle. Also carried by this assembly are pressure-indicator means 23 and a suitably elongated and configurated discharge conduit 24, which is shown additionally, supported by a bracket 25 secured to the motor 10 near the discharge end.

The valve body 19 is shown elongated and tubular, having a through passage extending from a lower or tankconnection end, to an upper or actuator-connection end. This passage preferably comprises a smaller straight cylindrical bore 26 at the upper end and a larger straight cylindrical bore 27 at the lower end; a conical valve seat 28 joins bores 26-27 at an inner location. The flare of seat 28 is preferably in the range of 20 to 50 with respect to the bore axis.

At its lower end, body 19 is secured to the open mouth of tank 20 by threads 30 and sealed by an O-ring 31 carried in a peripheral groove at the reduced end of body 19, the seal fit being within a smooth cylindrical counterbore 32 at the tank mouth. A tank-discharge pipe 33, extending into the inner volume of tank 20 includes an upper-end bushing 34 threadedly engaged to the lower end of bore 27.

An elongated valve stem 35 has an elongated upper cylindrical portion 36 in close (but not critically close) radial clearance with the upper bore 26, so that this fact alone accounts for a degree of coaxial alignment of the stem 35. An O-ring 37 is seated in a peripheral groove 38 near the lower end of stem portion 36; the fit of O-ring 37 to the bore 26 is compressional, assuring a pressure seal when the extinguisher is operated. To maximize the area available for extinguisher discharge, the lower end 39 of valve stem 35 is of reduced diameter; at its lower end, it carries a conical valve member 40 having a peripheral groove 41 for the support of an O-ring 42, in radial overlap with the flare of seat 28. Seat engagement is sealed by O-ring compression, and the rigid remainder of valve member 40, being also in radial overlap with seat 28, serves as a positive stop against ejection of the valve stem, even under the strongest pressures.

Discharge means 24 is connected at 43 to body 19, in communication with the upper bore 26, and at a location intermediate-the O-rings 37-42. Finally, pressure indicator 23 is connected to body 19 at a port 44 which communicates with the larger bore 27, i.e., below the O-ring 42.

In order to set up our extinguisher for use, the tank 20 is first filled with the desired extinguisher materials. The valve body, including attached tank-discharge pipe 33, is then secured and sealed to the tank mouth. Charging to requisite pressure is accomplished via line 24 or port 44, and in FIG. 2 we show that the gage connection 45 may include a T fitting 46 and shut-01f valve 47 for the charging-pressure line 48. Thus, to charge the system, compressed gas is admitted at 48, with valve 47 in open position. To avoid premature initial exhaust, the head 50 may be lifted by hand in order to seat valve member 40-41; alternatively, a relatively weak coil spring 51 will normally urge valve member 40-41 to closed position. Charging is complete upon indication of sufiicient gage pressure at 23. At this point, valve 47 is closed and the charging supply removed.

In case of an engine fire, usually around the carburetor, gas in bulb 14 will quickly respond to develop pressure under cap 17 and over diaphragm 18. An actuator pin or button 52 is thus displaced into contact with the head 50 of the valve stem. Rising pressure soon (e.g., in five seconds after the fire starts) displaces the valve stem 35 to unseat member 40-41. The pressurized gas in tank 20 then drives extinguisher material up pipe 33 to the discharge port 43 to the spray nozzle system. The short time delay, coupled with discharge in great volume in the fire region, combine to assure quick smothering action, and another vehicle is thereby saved from needless destruction.

It will be seen that we have provided an improved extinguisher system of elemental simplicity. Once triggered, the full contents of the extinguisher are rapidly discharged. The charged condition can always be observed at gage 23, which need not involve a needle (quantitative data) but may be merely a simple go or no-go device such as a red indicator against a window, should pressure drop to an inadequate level.

As to heat-detector response, this can be periodically rechecked and calibrated by inserting a suitable tool through an access window 54 in the side of the base 55 which connects the diaphragm 18 and cap 17 to the valve body 19. The axial clearance between actuator stem 52 and head 50 allows for insertion of a force-measuring tool, referenced on the base 55 (independently of head 50) and tracking the diaphragm-urged displacement force in response to known heat inputs at bulb 14.

Although the invention has been described in detail for the preferred form shown, it will be understood that modifications may be made without departing from the scope of the invention.

We claim:

1. In an automatic fire extinguisher, a tank for containing extinguishing material and having a threaded open month, an elongated valve body having a continuous through passage, said body being threadedly engaged at one end to the mouth of said tank to connect said passage to the interior of the tank, the bore of said passage at the tank-connection end being of larger cross-sectional area than the bore at the other end of said passage, said passage having a conic valve-seat region connecting the smaller and larger bores thereof, an elongated valve stem reciprocable in the smaller bore of said passage, a head on said stem in axial clearance with the other end of said passage, a valve member on the other end of said stern and having a peripheral groove radially overlapping said conic region, a resilient O-ring seated in said groove and constituting the seat-engaging part of said valve member, said seat-engaging part being disengaged from said seat when said axial clearance is reduced, said stem having a second peripheral groove at a location intermediate said valve-member and head ends, a second resilient 0 ring seated in said second groove under sealing compression against the adjacent wall of said passage, a spray-discharge port at the side of said body and communicating with said passage between the longitudinal locations of said O-rings, and heat-responsive mechanical-displacement actuator means carried at the head end of said body and including an actuating clement axially moved into operative engagement with said head upon detection of a predetermined heat condition.

2. The extinguisher of claim 1, in which an elongated tubular tankdischarge pipe is coupled to the tank-connection end of said body and extends into the interior volume of the tank.

3. The extinguisher of claim 1, in which pressure-indicating means is carried by said body in communication with said passage between said valvemember O-ring and the tank-connection end of said body.

4. The extinguisher of claim 1, in which said actuating element includes a pressure-responsive diaphragm, and

References Cited UNITED STATES PATENTS 855,076 5/1907 Thompson 169-20 1,616,974 2/ 1927 Josephson 169--2 1,744,733 l/ 1930 Beames 169-2 2,497,286 2/ 1950 Ashcraft 169-26 ROBERT B. REEVES, Primary Examiner H. S. LANE, Assistant Examiner US. Cl. X.R. 16919, 31, 42 

